Braiding machine

ABSTRACT

A braiding machine for applying a braided sheath of wire, yarn, thread, or other filamentary material to pipes, tubes, cables, wires and the like. The machine comprises at least one guide having arcuate guide surfaces of alternating curvature extending about the axis along which is positioned the article to be braided. The multiplicity of spindles carrying the filamentary element and mounted upon the freely rotatable pin are carried by nonrotatable feet or supports which are entrained along the guide surfaces by rotating disks having recesses along their peripheries.

United States Paten Petzetakis July 31, 1973 BRAIDING MACHINE 521,019 6 1894 Dmek 87 50 1,165,361 121915 P 87 38 [761 Invent: Arismwul 1,470.920 10/1923 11:15 0 87/55 Thessaloniki Chandri 1,541,792 6/1925 Conno1ly.... 87/55 x Moschaton/ ae Greece 1,766,683 6/1930 Petersen.... 87/55 x 1,989,369 1/1935 Krenzler 87/55 X [22] July 1970 2,019,777 11 1935 Cloutier 87 55 x 21' App], 57,719 3,408,894 11/1968 Kaufmann et a1. 87/50 X Primary Examiner-John Petrakes [30] Foreign Application Priority Data mmmey Karl E Ross Aug. 8, 1969 Greece 40785 52 U.S. c1 87/29, 87/50, 87/55 ABSTRACT CL n machine for a braided hgath of Fleld of Search 33, 34, 37, wire yam thread or other filamentary material to 1 87/38, 51, 54, 55 pipes, tubes, cables, wires and the like. The machine 7 comprises at least one guide having arcuate guide surl References (31ml faces of alternating curvature extending'about the axis UNITED STATES PATENTS along which is positioned the article to be braided. The 3,363,502 1/1968 Florentine et a1. 87/38 multiplicity Spindles carrying the filamentary 412,369 10/1889 Drawbaugh 87/34 x mm and mounted p the freely rotatable p are 889,311 6/1908 Jones 87/34 carried by nonrotatable feet or supports which are en- 1,011,632 12/1911 Luthe 87/37 trained along the guide surfaces by rotating disks havl,358,l73 ll/l92o Penso et 87/38 X recesses along their peripheries. 2,148,164 2/1939 Krippendorf 87/37 I 3/1968 Koreki et a1. 87/37 7 Claims, 14 Drawing Figures PATENIEDJUL 3 1 192a SHEET 2 OF 4 INVEN'IORI Arlsfovoulos 6. Pefzefakis jams M Attorney PAIENIED JUL3 1 1975 sum 3 or 4 Arisfovoulos 6. Pefzefakis INVENTOR.

PAIENIEDJUWW 3,748,952

SHEEI (If 4 Arisfovoulos G. Pefzefakis INVENTOR.

Attorney BRAIDING MACHINE Field of the Invention My present invention relates to braiding machines and, more particularly, to apparatus for forming a braided sheath of filamentary materials around an elongated member.

Background of the Invention Braiding machines have been proposed heretofore for forming a braided sheath of filamentary material, e.g. wire, thread, cord, yarn and synthetic-resin filament, about a central elongated member, i.e., a tube, pipe, cable, wire, or the like.

In conventional machines for this purpose, a number of rotating spindles each carry a spool of the filamentary material and rotate the member to be sheathed in the bread. The spools sweep in opposite directions alternately about the central member and pass alternately over and under one another to thereby wind the filamentary material about the member with crossover points so that the resulting coil of the filamentary material, formed on the central member, is a braid.

In accordance with conventional practices the braid comprises a plurality of strands each of which passes over and under the other strands as they are wound about the central member. Hereinafter reference will be made to strands and filamentary material," both terms being intended to refer to elongated flexible elements capable of being braided into a sheath around an elongated member. Also, the term member, when used in this sense, is intended to designate substantially any core element of elongated configuration about which it is desired to form a braid. Generally, the strand is derived from a spool or bobbin, these terms being used to designate the package, consisting of a central core or sleeve, and carrying along the exterior thereof a large number of threads of the strand. However, the expression is considered sufficiently broad to encompass yarn packages and the like which have no central core or spool, and packages from which the strand may be drawn from the center or from the exterior.

In the aforementioned conventional braiding machines, a number of spindles, each carrying the respective spool, orbit the central member and are swung excentrically with respect to the axis of the orbit. The spindles may in turn sweep along circular arcs centered upon points or axis located along a circle which, in turn, is centered upon the central member.

It has been proposed in such systems to provide supports for the spindles which are rotationally fixed thereto and to use flywheels'or the like to carry spindles along their orbiting paths. In substantially all such machines, however, the braiding speed is limited by virtue of the fact that the spindles frequently changed direction and velocity along the path to produce the crossover points of the strands, and at such times there is an abrupt change in the kinetic energy. Excessive speeds, coupled with abrupt changes in kinetic energy, cause vibrational stresses which have hitherto limited the speed of the apparatus. The same considerations also have limited the size of the strand package which could be carried by the spool and hence the capacity of the machine.

A particularly advantageous use of a braiding machine is in conjunction with an extrusion apparatus from which the elongated member, i.e., tube or cable, emerges at a relatively high rate. It is desirable to braid the outer sheath on this member at the rate at which the member emerges from the extrusion machine. With conventional systems this has not been possible.

Finally, a key disadvantage of earlier machines for the formation of braid around a central member resides in the fact that the parts which are guided often engage the guided surfaces with considerable friction. The friction effect, accompanied by substantial wear of the moving parts, is increased as the speed of the apparatus increases.

For all of the foregoing reasons conventional braiding apparatus has been of limited size and speed and, to the best knowledge of applicant, earlier efforts to solve these problems have proved to be unsuccessful.

OBJECTS OF THE INVENTION It is, therefore, the principal object of the present invention to provide a braiding apparatus for the pur poses described which can operate at higher speeds than those possible heretofore.

Another object of the invention is to provide a braiding machine for forming braided sheaths around tubes, pipes, cables, wires, and the like, which is able to form a braid with multiplecrossovers, but without the substantial disadvantages arising from the changes in kinetic energy which have hitherto characterized the operation of earlier devices.

A further object of the instant invention is to provide an improved braiding machine which eliminates the disadvantages enumerated above. I

It is another object of my invention to provide an improved braiding machine which can operate to form a SUMMARY OF THE INVENTION It has now been found that these objects can be achieved in a braiding machine in which the spoolsor bobbin (packages) of filamentary material or strands are carried on spindles or rods which are freely rotatable in axial-support feet therefor, the feet being guided in an orbit about the member to be surrounded by the braid.

According to an essential feature of this invention, the guide surfaces surrounding the member to be braided are circular arcs of alternating concavity or direction of curvature while the feet are guided along these surfaces alternately along a convex path and a concave path around the central member to be enclosed in the sheath. Generally, therefore, two sets of spools are provided to orbit the central member in opposite directions whereby one set of spools is displaced along a concave portion of the of the path (with reference to the center of the orbit), while, the spools of the other set pass along a convex path in the same region. Consequently the spools of the two sets will continuously cross over the paths of one another, producing the strand crossover points required for braiding. The means for displacing the spools includes a plurality of rotatable disks or flywheels centered upon a circle coaxial with the orbit, each of the disk axis being located at the center of curvature of the respective guide surfaces so that the disks entrain the axial supports of the spools along the respective arcuate sections upon engagement of the rods or spindles in recesses formed along the peripheries of the disks.

Advantageously, the disks are displaced in substantially tangential or osculating relationship and rotate in opposite senses, while having pockets or recesses formed along their peripheries and designed to embrace the spindles. The latter may carry bearings for engagement by the disks to enable the spindles to rotate freely. The orbital nature of the guide path, furthermore, allows large-diameter members to be surrounded -with the braid.

From the foregoing it will be apparent that a braiding machine according to the invention (for forming braided sheaths upon tubes, pipes, cables, wires and the like) is provided with driven flywheels, support-guide paths associated with each of the flywheels, and a plurality of axial supports for the spools or packages of the strand, each of the axial supports including a support foot or shoe engaging the guide surface and a support spindle freely rotatable in the foot and carrying the spindle. I

As noted earlier, the spool may consist of an internal sleeve or core carrying the package of the strand, the spindle or rod being received 'in recesses of the flywheel. It will be recalled that in conventional (priorart) apparatus the axial support for the spindle created the imbalance causing much of the difficulty. In accordance with the system of the present invention, the axial support of the spindle is guided along its path without rotation while the spindle is permitted to rotate freely, hence imbalance cannot occur, nor are abrupt changes in kinetic energy produced. As a result, a simplified construction is obtained and operation at high speeds and with large capacity spools is possible.

According to a more specific feature of this invention, the recesses of the flywheels engage the spindles between the guide shoes and the strand package, preferably, as close to the shoes and spindles as is possible. Between the recesses and the spindles I may provide ball-type or roller-type hearings to limit frictional retardation in the rotation of the spindle. Advantageously, the bearings engaged by the spindles are constituted as rotatable sleeves or rings which are mounted upon the spindles andare peripherally engaged by the disks. All of the elements at which relative rotation can occur are connected by roller bearings or ball bearings designed for low-friction operation and movement with minimum play.

I have also discovered that it is possible to provide the guide ways in an 8 (figure-eight) configuration and yet eliminate shocks at the transfer between the arcuate portions of the guide paths by continuing these arcuate portions as circular arcs of identical radius of curvature but with the direction of curvature alternating from section to section. On the one hand, therefore, the support feet or shoes constantly constantly are held against the guide surfaces, while on the other hand they are supported by the disks.

Description of the Figures The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a diagrammatical plan view of an upper portion of a guide plate of a braiding machine according to the present invention;

FIG. 2 is an elevational view of one of the spindle assemblies taken in the-direction of arrow II of FIG. 1;

FIG. 3 is a cross section taken along the line III III of FIG. 2;

FIG. 4 is a view similar to FIG. 1 but illustrates another embodiment;

FIG. 5 is a view in the direction of arrow V showing the yarn package in elevation (partially broken away);

FIG. 6 is a section along the line VI VI of FIG. 5;

FIG. 7 is a plan view diagrammatically illustrating the guide ways of the upper plate of the system of FIG. 4;

FIG. 8 is an elevational view of the portion of the assembly represented by arrow VIII of FIG. 7;

FIG. 9 is an elevational view showing another embodiment of the system of FIG. 8;

FIG. 10 illustrates a modified arrangement of the spindles;

FIGS. 11 and 12.are diagrammatic views similar to FIG. 1 but illustrating other embodiments of the invention;

FIG. 13 is a detail view showing the shoe in accordance with an other aspect of the invention; and

FIG. 14 is a diagram illustrating the braided product.

From FIG. 14 it will be apparent that the present invention comprises a machine for forming a braid B about an elongated member M, here shown to be a tube emerging from an extruder E. The braid B consists of four or more strands S and S wound about the member M so that each strand crosses over and under successive strands of the other set on the crossover points K.

SPECIFIC DESCRIPTION In FIG. 7 the object G, to be encased with the braided sheath, is surrounded by a plate 12 in which are formed a pair of guideways W and W, respectively, these guideways being formed from arcuate sections 2 of alternating curvature.

As is also apparent from FIG. 7, the guide surfaces 2 cooperate with flywheels or disks 1 which are provided along their peripheries with outwardly open recesses 9 adapted to engage the spindles. The feet or shoes providing axial support for the spindles 4 are here represented at 5 and are shown to be generally rectangular with curved outer surfaces corresponding to the curvature of the surfaces 2.

In order to appreciate the operation of the system, it should be assumed that the shoes 5 carry the spindles 4 which are freely rotatable, in accordance with the main feature of this invention, and further carry the spools 6 from which the strands are led to the sheath of braid surrounding the member G. One such strand is represented for oneset of spindles at S while the oppositely moving strands are represented by the strand S. The guide surface 2 of the first set of strands, represented at the top in FIG. 7, is shown to be concave in the direction of the axis A of the orbit and to have a radius of curvature R centered at C, this being the center of rotation of the upper disk 1 as well.

Advantageously, the disks come approximately into contact at their osculation points 0. A shoe 5a of the first set is thus displaced by the uppermost disk 1 in the counterclockwise sense along the concave guide surface 20 which merges at 20' with a guide surface 2b along which the opposite flank of the shoe 5a is advanced by the next disk lb. The guide surface 2b is of the same radius of curvature R and is shown to be located in the upper left-hand quadrant of the apparatus. However, this surface is concave away from the axis A of the orbit. Consequently, the shoe 5a is guided alternately along surfaces concave toward the axis and concave away from the axis as it orbits the member G to be encased in the braided sheath.

Simultaneously, the shoes 5b of the oppositely moving set are carried along the outer edge of the oppositely rotating flywheel or disk 11; and the guide surface W thereof which is shown to have the same radius of curvature R as the remaining surfaces, but to be oppositely oriented with respect to the surface 2b. In this case, the guide surface has a concavity toward the axis A and merges with the surface 20 which is concave away from the axis and is coordinated with the previously mentioned surface 20. Hence the shoes Sb will orbit the axis A and the object G in the clockwise direction, alternately carrying along the outer semicircumference of the disks 1b which rotate in the clockwise sense, but along the inner semicircumference of each disk la rotated in the counterclockwise sense. The shoes 5b continuously move in the clockwise sense, as noted, whereas the shoes 5a are continuously carried in the counterclockwise sense about the axis A as they are engaged along the outer semicircumference of each counterclockwise-rotating disk 1a but along the inner semicircumference of each clockwise-rotating disk. The result is a figure-eight movement of the shoes among each pair of disks and a crossover of the strands S and S in accordance with conventional braiding practices.

As is diagrammatically illustrated in FIGS. 1 3, the filament package 6 comprises a spool 7 and the strand 8 which is wound thereon. The strand passes upwardly and enters a tube 8 overlying the spool and affixed to the spindle or support rod 4 which is likewise tubular and from which the strand 8 is led to the object to be braided.

The rod 4 may also carry a removable housing or shield 4a which encloses the spool 7. The spool, of course, is removably mounted on the spindle 4 to enable replacement of an empty strand package with a full one. According to the principles of the present invention, the spindle 4 is rotatably received within the shoes 5, two of which are provided in axially spaced relationship on either side of the package 6. I have found that best results are obtained when two such shoes are used and, for example, the upper shoe of each pair engages one set of arcuate guide surfaces (e.g. the guide surfaces W), while the lower set is used for engagement of the other set of guide surfaces W, the assembly being interchangeably movable in either the clockwise or counterclockwise orbit about the object.

The shoes may have the configuration illustrated in either FIG. 3 or FIG. 6 as will be apparent hereinafter. In the configuration of FIG. 3, the shoe 105 is shown to be a roller or sleeve which rotates as the assembly is led along the guide surfaces 2. To permit free rotation of the spindle 4, the latter is fixed in the inner race 10' of a ball bearing 10 whose outer race forms the roller portion of member 105 which engages the surfaces 2. In the embodiment of FIG. 6, however, the shoe 5 is an ovoid rectangle as described in connection with FIG. 7 and has flanks 5 and 5", engageable with the surfaces 2. Preferably, the surfaces 5' and 5" have radii of curvature R equal to that of the surfaces 2 to be engaged thereby. The leading and trailing edges 5" connect with the flanks 5, 5" with rounded corners to permit a smooth transition between surfaces 2 of opposite curvature. The term opposite curvature" as used herein, is intended to refer to the direction of curvature of surfaces of equal radii. As is also apparent from FIGS. 1 3, the spindle 4 carries between the package 6 and each pair of shoes 105, ball bearings 11 whose inner races are mounted upon the spindles 4 and whose outer races are engaged in the recesses 9 of the flywheels or disks 1. The recesses 9 conform to the bearings 11 over a semicircle thereof.

As is shown in FIGS. 1, 4 and 7, the guide surfaces 2 are circular arcs with equal and constant radii of curvature R whereby only the direction of curvature varies from one guide surface to another along the orbit of the assemblies. The assemblies are, therefore, guided only over a part of each rotation of the flywheel or disk 1 and are thereupon transferred to the next flywheel which moves in the opposite sense.

FIGS. 2 and 5 illustrate the position of the bearings 11 for a system using two pair of shoes and one pair of spindle-support shoes 5, respectively, it being understood that it is the preferred case to locate the bearings 11 engaged by the wheels 1 between the shoes and the packages. In any event, vibration can be reduced to a minimum when the wheels 1 engage each spindle between a pair of shoes as is the case with both FIGS. 2 and 5, when two wheels 1 are provided on a common shaft and bracket. The package 6 (FIGS. 2 and 5), or when two wheel disks are provided on a single shaft and engage the spindle between a pair of shoes (FIGS. 2 and 5). Other arrangements are, however, possible as has been illustrated in FIGS. 8 10.

For example, it is possible to provide an engagement of the spindle only on one side of the yarn package (FIG. 10) in which case a pair of wheel disks 1 are provided on a common shaft and engage the spindle 4 at axially spaced locations along the side of the spindles opposite the strand package from the shoes 5. Here, of course, the shoes may be either rollers as illustrated in FIG. I or blocks as shown in FIG. 4.

FIG. 10 also represents an embodiment wherein the filament spools 7 are provided on opposite sides of the disks alternately. For example, it has been found to be advantageous, with this arrangement, to provide all of the clockwise-orbiting spools 7 as upper units and all of the counterclockwise-orbiting units below the horizontal median plane F along which a support plate can be provided. Both flywheels or disks 1, however, operate to retain units of each set against the respective guides.

In the system of FIG. 8, l have shown an arrangement wherein the two flywheels are disks of a common shaft I flanking packages 8 in the manner previously described with reference to FIG. 2 and two filament units move in opposing orbits lying in a common plane. In this case, the shoes 5 of one unit are located axially outwardly of the shoes of the other unit for engagement with the respective guide surfaces. Assuming, therefore, that the right-hand unit is a member of the set of packages orbiting in the counterclockwise sense, there will be provided an upper plate and a lower plate formed with the surfaces 2a, 2b engageable with the shoes of this unit. Below the upper plate and above the lower plate, there is provided another pair of plates with guide surfaces corresponding to those represented at W and engageable with the shoes of the left-hand or clockwise-orbiting strand packages.

Still another modification is represented in FIG. 9 in which the strand-carrying units 3 are located in different axial planes symmetrically with respect to a horizontal median plane between the flying wheels 1. in this embodiment the counterclockwise-orbiting or righthand unit 3 is constituted as a lower unit and has its upper and lower shoes 5 disposed axially above the corresponding shoes of the clockwise-orbiting or left-hand unit 3. Here again, the wheels 1 flank each unit 3 and engage the spindles 4 between the respective shoes and the strand packages. The guide surfaces of the counterclockwise-orbiting unit are formed on plates located above the plates of the clockwise-orbiting unit in accordance'with the principles previously discussed. A separate motor M may be provided for each shaft 1 of the flywheels or disks 1, in which case all of the motors are electronically synchronized or rotation at precisely the same speed. Alternatively, a gear, timing chain or like transmission may be provided between the shafts which can then be driven by a single motor M.

As will be apparent from FIGS. 11 13, the guide surfaces 2 can be constituted in various ways. In FIG. 13, for example, the guide surface is shown to be a slot 202 formed in the guide plate 212 and slidably receiving an oval shoe 205 which supports via a bearing 210, the spindle 4 of the system. As shown in FIG. 11, however, the guide surfaces may be internally engaged by a planetary strand-carrying unit 3. In this case, guide disks 13 are provided with the guide surface and are coaxial with the wheels or disks 1. The semi-circular collar-shaped surfaces 14 formed by these disks, therefore, correspond to the guide surface 2 previously described. The axial support for the spindle, in this case, includes an arm 15 provided at its extremities with rollers 305 corresponding to the shoes. While the radii of curvature of these surfaces are identical, although they are curved in opposite directions with respect to the central member, they are less by a factor determined by the length of arm 15 than the radii of the curvature R previously described. At the transition between surfaces, one roller 305 disengages from its guide surface 14 while the otherroller of the arm is brought into engagement with the successive surface.

FIG. 12 represents a similar system wherein, in place of the roller 305 the arm 15 carries arcuate guide blocks 405 of a curvature identical to that of the surface 14.

The improvement described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the invention except as limited by the appended claims.

l claim:

1. A braiding machine for forming a braided sheath of strands upon a generally central elongated member, said machine comprising:

means including a plurality of arcuate guide surfaces of alternately opposite curvature around said member and defining a guide path surrounding same;

a multiplicity of strand carriers each having a shoe bearing against said surfaces while being shiftable along said path and guided thereby, a spindle freely rotatable on said shoe centrally thereof and a strand package carried by said spindle for paying out a strand onto said member, said shoes being each formed as arms extending diametrically of the respective spindle and provided at opposite ends with follower elements alternately engageable with said surfaces; and a plurality of wheels arrayed about said member and provided with peripheral recesses successively engaging said spindles and r0 tatable to displace said carriers along orbits around said member and along said path and to transfer said strand carriers from wheel to wheel around said member, said spindles being received in said recesses, said surfaces being formed on disks concentric with said wheels.

2. The braiding machine defined in claim 1 wherein said follower elements are rollers engaging said surfaces.

3. The braiding machine defined in claim 1 wherein said follower elements are guide blocks slidably engaging said surfaces.

4. The braiding machine defined in claim 1, further comprising bearing means between said spindle and said shoe for rotatably journaling said spindle on said shoe.

5. The braiding machine defined in claim 4 wherein each of said spindles is provided with a freely rotatable bearing sleeve engageable in said recesses.

6. The braiding machine defined in claim 1 wherein a pair of coaxial wheels are rotatable about each of said axes for joint engagement with the respective carriers, said spindles being each provided with a pair of such shoes in axial alignment for engaging axially spaced guide surfaces of said path.

7. The braiding machine defined in claim 6 wherein said carriers are provided in at least two sets, the packages of the carriers of one set being axially offset from the package of the carrier of the other set. 

1. A braiding machine for forming a braided sheath of strands upon a generally central elongated member, said machine comprising: means including a plurality of arcuate guide surfaces of alternately opposite curvature around said member and defining a guide path surrounding same; a multiplicity of strand carriers each having a shoe bearing against said surfaces while being shiftable along said path and guided thereby, a spindle freely rotatable on said shoe centrally thereof and a strand package carried by said spindle for paying out a strand onto said member, said shoes being each formed as arms extending diametrically of the respective spindle and provided at opposite ends with follower elements alternately engageable with said surfaces; and a plurality of wheels arrayed about said member and provided with peripheral recesses successively engaging said spindles and rotatable to displace said carriers along orbits around said member and along said path and to transfer said strand carriers from wheel to wheel around said member, said spindles being received in said recesses, said surfaces being formed on disks concentric with said wheels.
 2. The braiding machine defined in claim 1 wherein said follower elements are rollers engaging said surfaces.
 3. The braiding machine defined in claim 1 wherein said follower elements are guide blocks slidably engaging said surfaces.
 4. The braiding machine defined in claim 1, further comprising bearing means between said spindle and said shoe for rotatably journaling said spindle on said shoe.
 5. The braiding machine defined in claim 4 wherein each of said spindles is provided with a freely rotatable bearing sleeve engageable in said recesses.
 6. The braiding machine defined in claim 1 wherein a pair of coaxial wheels are rotatable about each of said axes for joint engagement with the respective carriers, said spindles being each provided with a pair of such shoes in axial alignment for engaging axially spaced guide surfaces of said path.
 7. The braiding machine defined in claim 6 wherein said carriers are provided in at least two sets, the packages of the carriers of one set being axially offset from the package of the carrier of the other set. 